Selectivity enhancement of Co-Mo/Al2O3 FCC gasoline hydrodesulfurization catalysts via incorporation of mesoporous Si-SBA-15

Mesoporous Si-SBA-15 was applied to enhance the FCC gasoline selective hydrodesulfurization (HDS) performance of conventional Co-Mo/Al2O3 catalysts and the physicochemical properties of the resulting catalyst were compared with those of Co-Mo/Al2O3 catalysts incorporated with macroporous kaolin, mesoporous Si-MCM-41 and microporous Si-ZSM-5. The selective HDS performances of all the catalysts were assessed with different FCC gasolines as feedstocks. The results showed that the HDS selectivity of the catalysts was closely related to the Mo sulfidation that depends on catalyst surface area and metal-support interaction. With the superior Mo sulfidation, the Co-Mo/Si-SBA-15–Al2O3 catalyst had the optimal HDS selectivity for not only the full-range FCC gasolines but also the heavy fractions thereof. The present article demonstrates the significance of enhancing Mo sulfidation in improving HDS selectivity and thus sheds a light on the development of highly selective HDS catalysts.

Research highlights
► Incorporation of Si-SBA-15 into Co-Mo/Al2O3 increases catalyst surface area.
► Incorporation of Si-SBA-15 weakens the metal-support interaction in Co-Mo/Al2O3.
► The two effects enhance the Mo sulfidation and thus HDS selectivity of the catalyst.